The present invention relates to pharmaceutical compositions of nitrites such as inorganic nitrites, or any pharmaceutically acceptable salts, solvates, or prodrugs thereof, and the medical use of these compositions. The pharmaceutical compositions, which can be formulated for oral administration, can provide immediate release or extended release of the nitrite ion (NO2−；). The pharmaceutical compositions of the invention are useful, for example, for treating or reducing pain, improving symptoms of a microvascular disease, and improving nerve conduction velocity.
